Some work activities result in harmful substances contaminating the air in the form of dust, mist, gas or fume. For example, cutting a material such as stone, concrete or wood, using a liquid containing volatile solvents or handling a dusty powder. Similarly, workers may also need to work in areas where oxygen levels are low, for example: confined spaces, such as a chamber or tank. In such instances it is likely the individuals concerned will need to wear RPE or Respiratory Protective Equipment.

Where RPE is used in a work process, it must be able to provide adequate protection for individual wearers. RPE can’t protect the wearer if it leaks. A major cause of leaks is poor fit – tight-fitting facepieces which need to fit the wearer’s face to be effective. As people come in all sorts of shapes and sizes it is unlikely that one particular type or size of RPE facepiece will fit everyone. Fit testing will ensure that the RPE selected is suitable for the wearer.

There are two types of face fit testing, Qualitative and Quantitative.

Qualitative fit testing is a pass/fail test based on the wearer’s subjective assessment of any leakage from the face seal region, by sensing the introduction of a test agent. These tests are suitable for half masks. They are not suitable for full face masks. Examples of qualitative fit testing methods are:  method based on bitter- or sweet-tasting aerosol; method based on odour compounds.

Quantitative fit testing provides a numerical measure of the fit, called a fit factor. These tests give an objective measure of face fit. They require specialised equipment and are more complicated to carry out than qualitative methods. Quantitative methods are suitable for full face masks (but can also be used for half masks). Examples of quantitative fit testing methods are: laboratory test chamber; portable fit test devices, such as a particle counting device.

Kays Medical can provide face fit testing required against the identified RPE in the appropriate COSHH risk assessment.